The present study considers the possibility of developing an integrated system for monitoring the basic parameters of the braking system of cars in operation during the braking process. The main parameters determining the braking efficiency of cars are the temperature of the brake system elements and the brake fluid pressure. Experimental studies and developments have been carried out to determine the temperature of the car's brake discs during braking.

This article presents the results of experimental studies of harmful components contained in the exhaust gases from internal combustion engines in cars. The exp

Over the past 30–40 years, vehicle tailpipe emissions of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HCs) have decreased significantly. Advanced emission after-treatment technologies have been developed for gasoline and diesel vehicles to meet increasingly stringent regulations, yielding absolute emission reductions from the fleet despite increased vehicle travel. Passenger cars are an important source of air pollution, especially in urban areas. Recently, real-driving emissions (RDE) test procedures have been introduced in the EU aiming to evaluate nitrogen oxides (NOx) and particulate number (PN) emissions from passenger cars during on-road operation. Although RDE accounts for a large variety of real-world driving, it excludes certain driving situations by setting boundary conditions (e.g., in relation to altitude, temperature or dynamic driving). The present work investigates the on-road emissions of NOx, NO2, CO, particle number (PN) and CO2 from a vehicles, including diesel, gasoline, liquid petroleum gas (LPG) and compressed natural gas (CNG) vehicles. The vehicles were tested under different on-road driving conditions outside boundaries. These included ‘baseline’ tests, but also testing conditions beyond the RDE boundary conditions to investigate the performance of the emissions control devices in demanding situations.

In recent decades, environmental requirements for reducing the toxic components emitted from vehicle exhausts have decreased drastically. Technologies for after-treatment of diesel vehicle emissions are being improved continuously in order to meet increasingly stringent regulations. Passenger cars are a significant source of air pollution, especially in urban areas. The EU has decided to phase out internal combustion engines. Stricter Real Driving Emissions (RDE) testing procedures have also been introduced, aiming to assess the emissions of nitrogen oxides (NO_x) and particle number (PN). The present work investigates the interaction between performance and smoke emissions of a diesel vehicle on a pre-established route in an urban environment with an everyday (normal) driving style. The results showed that when the vehicle is technically sound and meets its technical specifications, smoke emissions are within normal limits.

This study presents a single-case multi-sensor experimental study of thermal loading and emission variation in a high-mileage gasoline engine operating at idle under deliberately impaired cooling until mechanical failure. A production vehicle equipped with a naturally aspirated gasoline engine with a displacement of 1600 cc was operated under relatively steady-state conditions at idle, while gaseous emissions (CO, CO₂, HC, NO_x, and O₂), air–fuel ratio λ, particle number (PN), oil temperature, infrared thermal indicators, and acoustic performance variation were continuously monitored. The results are interpreted primarily in terms of their dependence on the engine oil temperature. They show that despite stable conditions of the air–fuel ratio and an almost constant amount of residual oxygen in the exhaust gases, progressive thermal loading leads to pronounced changes in the behavior of the emissions emitted by the engine during its operation. Hydrocarbon emissions show increased variability and escalation at elevated engine oil temperatures, while nitrogen oxides show a strong temperature-dependent increase, consistent with thermally driven formation mechanisms. The most significant response is observed in the particle number (PN) emissions, which go from low and stable levels to a rapid, multi-step increase in a narrow temperature range preceding mechanical failure. Under the tested cooling impairment scenario, emission behavior was dominated by cumulative thermal stress rather than mixture composition effects. In the investigated case, particle number emissions emerged as a sensitive indicator of system-level thermal instability. The findings provide experimentally documented insight into the system-level progression toward thermal runaway under impaired cooling conditions and its measurable impact on emission behavior in the tested engine.

The safe crossing of pedestrians at traffic light-regulated intersections is ensured by the permissive and prohibitive signals provided for them and by certain priority rules that drivers in traffic flows conflicting with pedestrians must comply with. This in turn leads to the occurrence of traffic delays, which are inevitable under certain traffic conditions. The present study focuses on determining the length of traffic delays when pedestrians cross at a traffic light-regulated intersection in the city of Sofia, Republic of Bulgaria. The intersection was selected due to the high intensity of pedestrian flows established in preliminary random observations, which is provoked by its location. The study includes determining the traffic delays over a period of 12 h with full readings of these indicators for each cycle of the traffic light system during the morning and evening peak periods and with partial readings for 15 min for each cycle in the remaining hours of the study period. The results show the lack of a relationship between the waiting time of vehicles and the number of pedestrians crossing. Such an influence can be sought in the behavior and types of pedestrians and the intervals at which they enter the crosswalk. This study can assist researchers in this field in developing pedestrian crossing models and determining additional measures to increase their safety when crossing light-regulated intersections.